Lincoln, city (district), administrative and historic county of Lincolnshire, England. It stands 200 feet (60 metres) above sea level on an impressive site at the point where the River Witham cuts a deep gap through the limestone escarpment of the Lincoln Edge. Lincoln is the market centre for a major arable agricultural district, and many of its industries are agriculturally based, including food processing; it also has manufacturing of heavy machinery. The convergence of the major eastern English road and rail routes on Lincoln contributes to its importance.

Lincoln was a significant Roman town, then called Lindum, and it lay on the line of Fosse Way and Ermine Street and served as a fortress for the 9th Legion. By 71 ce it had become a colonia, Lindum Colonia, serving as a settlement for retired legionary soldiers. The town walls were first established in that period, and relics of them still remain, including Newport Arch. Exchequer Gate, Potter Gate, and Stonebow are medieval gates built much later. The many other Roman finds include a public fountain, cemeteries, baths, and kilns, and the museum has an extensive collection of Roman antiquities.

Lincoln became one of the five boroughs under Danish rule in eastern England, and by the late Middle Ages it was one of England’s major towns. Henry II gave the city its first charter in 1154, and citizens gained many privileges and a freedom somewhat similar to that of the City of London. Lincoln’s importance continued when, in 1291, it was made a staple (trading) town dealing in wool, leather, and skins, activities that contributed to its prosperity at the end of the 13th century.

Many of Lincoln’s famous buildings are medieval. Lincoln Castle, standing on the Lincoln Edge opposite the cathedral, dates from 1068 and contains Norman fragments. The castle keep dates from the 12th century. The cathedral, also Norman, stands on an elevated site overlooking the city. Built of local limestone, it is severely weathered on the outside, but inside it contains noted examples of Gothic architecture. The surrounding cathedral close contains the polygonal Chapter House (1225), the earliest English example of its kind. Area 14 square miles (36 square km). Pop. (2001) 85,595; (2011) 93,541.This article was most recently revised and updated by Kathleen Sheetz.